In recent years, with the increase in brightness of LEDs, the LEDs have been used widely in a backlight and a flashlight of a liquid crystal display of a cellular phone, traffic signals, a light source of an office automation equipment such as a printer, and a lighting device and so forth.
For example, an LED light source device in which heat generated from each of the plural packaged LEDs is dissipated by a heat sink and heat can be efficiently transmitted to a chassis of an attached lighting device has been disclosed (for example, refer to Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2004-55229 (paragraphs [0024] to [0025], FIG. 1)